Installation & Commissioning - Dräger REGARD 3900 Serie Gebrauchsanweisung

+ signal - 0 V
The 4-20 mA output signals duplicate the assigned input signals but are electrically
isolated from them. The signal outputs are current sources that only work if they are
connected to a passive load.
Input channel is inactive
Alarm lock
If the inhibit switch is moved to position 1, the output signals are frozen in their
current state.
If the inhibit switch is moved back to position 0, the output signals return to their
normal state.
Output module fault
In the event of a fault on the output module, all channels have an output signal of
1 mA (± 0.3 mA).
5 Installation & commissioning
5.1 General instructions
The following general instructions should be observed for all installation, repair or
maintenance work on the control unit. Information about the transmitters and
sensors can also be found in the "Instructions for Use" of the remote sensor
transmitter.
WARNING
Risk of electric shock!
A non-interrupted power supply can result in personal injury and/or damage to the
control unit, the remote sensor transmitter or the cable.
► Before installation, repair or maintenance work on the control unit, disconnect or
shut down all AC and DC power supplies to the control unit.
1. Disconnect or shut down all AC or DC power supplies to the control unit.
REGARD
Input signal (mA)
Below 3.8
3.8 to 4.2
4.3
12
20
Over 20
®
3900
Installation & commissioning
Reading on the display
(range 0–100)
Under-range or mainte-
nance
0
2
50
100
Over range
Display blank
Output channel signal
(mA)
As input signal
4.0
4.3
12
20
As input signal
0